This section provides background information related to the present disclosure which is not necessarily prior art.
Many vehicle exhaust systems use active and/or passive valve assemblies to alter the characteristics of exhaust flow through a conduit as the exhaust pressure increases due to increasing engine speed. Such valves can be used to reduce low frequency noise by directing exhaust through mufflers or other exhaust system components. For example, valves can direct exhaust flow past obstructions, which create vortices that absorb low frequency sound energy. Active valves carry the increased expense of requiring a specific actuating element, such as a solenoid. Passive valves utilize the pressure of the exhaust flow in the conduit to actuate the valve. Although passive valves are less expensive, traditional passive valves create unwanted back pressure when the valve is open, can be difficult to manufacture, and are susceptible to vibration related noise and excessive valve flutter caused by flowrate fluctuations in the engine's exhaust flow (i.e. exhaust pulsation). There is seen to be a need in the art for a passive valve that is relatively inexpensive to manufacture, is quieter than existing passive valves, and minimizes unwanted back pressure in the open position.